Patent application US 2006/0204840 describes an accumulator assembly formed by the alternate stacking of energy accumulator elements and stiffening plates. Fastening plates are provided for clamping the accumulator elements and plates together. These fastening plates have lugs for the passage of threaded rods interacting with nuts to form a unitary assembly.
There is also a known accumulator assembly, described in patent application US 2009/0017367, comprising a plurality of accumulator elements stacked against each other, two fastening plates at the ends of the stack, and stiffening members extending transversely between the plates and having housings adapted to receive the ends of the accumulator elements. The assembly further comprises threaded rods and nuts which are combined in order to fasten the members and keep the stack of accumulator elements assembled.
In this accumulator assembly, an electrical connecting plate is provided between the associated positive and negative electrodes of the adjacent accumulator elements. The positive electrode is mounted inside a hole formed in the connecting plate and is then soldered to the plate. The negative electrode is fastened to the plate by screwing. These operations are lengthy and costly.
U.S. Pat. No. 5,674,641 discloses another accumulator assembly which comprises a plurality of superimposed electrical energy accumulator elements, spacers positioned axially between the connecting electrodes of the accumulator elements, fastening rods extending axially through apertures in the connecting electrodes and spacers, and upper and lower end plates interacting with the rods for the assembly of the connecting electrodes and spacers.
WO 2006/068373 discloses another accumulator assembly comprising a plurality of accumulator elements stacked and mounted inside a receiving casing made in two parts. The connecting electrodes of the accumulator elements include apertures for the passage of threaded rods and a fastening for said rods on the lower part of the casing. Insulating spacers are positioned axially between the connecting electrodes of adjacent accumulator elements. These spacers support electrical connecting plates which connect the electrodes of the accumulator elements.
When these accumulator assemblies are installed, poor-quality plating of the connecting electrodes and of the means positioned axially between the electrodes may result in a defective flow of electric current.
Furthermore, in certain vehicle driving conditions, the vibrations to which these accumulator assemblies are subjected may cause a break in the electrical contact between the means positioned axially between the electrodes and the electrodes themselves. This also results in a defective supply of current.